Domain Model
   - Datatypes
     + Operations
   - Bridges
   - Object Model

Object Model
   - Object (Object-in-model encapsulates instance-in-time, so captures
     metamodel object and instance associations to other elements) 
   - Subtypes
   - Attributes
     + Attribute Derivations
   - Relationships
   - Methods
   - State Models

State Model
   - States
   - Events
   - Transitions
   - Process Models

Process Models
   - Variables
   - Values
   - Operations
   - Element References

